qiskit_addon_cutting.utils.observable_grouping.observables_restricted_to_subsystem¶
- observables_restricted_to_subsystem(qubits, global_observables, /)[source]¶
Restrict each observable to its support on a given subsystem.
A
PauliList
will be returned if aPauliList
is provided; otherwise, alist[Pauli]
will be returned.Any phase information will be discarded, consistent with the standard behavior when slicing a Pauli.
- Parameters:
qubits (Sequence[int]) – The qubits in a subsystem
global_observables (Sequence[Pauli] | PauliList) – The list of observables
- Return type:
list[Pauli] | PauliList
- Returns:
Each
Pauli
restricted to the subsystem.
>>> observables_restricted_to_subsystem([1, 3], PauliList(["IXYZ", "iZZXX"])) PauliList(['IY', 'ZX'])